1. Field of the Invention
The present invention relates to power generation systems, and particularly to an integrated solar-gas turbine cogeneration plant that produces power efficiently and economically with minimal impact on the environment.
2. Description of the Related Art
Energy consumption and carbon dioxide emissions have become an increasing concern in the power and steam generation industry. A typical power plant using fossil fuels can produce tons of waste products such as carbon dioxide on an annual basis, even with strict regulation. Moreover, important factors, such as the balance between energy input and output for producing the power and the economics thereof, must be carefully considered and monitored in order to sustain a profitable and efficient power plant.
Several different methods have been pursued in order to confront this problem. One solution lies in cogeneration. Cogeneration is the sequential production of electricity and heat, steam, or useful work from the same fuel source. It can be applied to any commercial, industrial, or institutional facility where there is a simultaneous need for both heat energy and electrical power. It offers several advantages over central electricity generating stations. Many of these advantages have been noted through energy and exergy analyses of cogeneration systems. Among these advantages are higher fuel efficiency, reduced operational costs and self-sustaining plant operation. Fuel efficiency is increased because the normally rejected heat, e.g., the excess heat from combusting fossil fuel, is used in other useful processes, such as hot water heating. Due to the increased efficiency, the amount of fuel and the costs thereof are lower than in a typical fossil fuel power plant, which equates to a more financially attractive operation. The power or electricity produced through cogeneration is often used to power the plant, which substantially reduces transmission line capacity and costs. Moreover, unlike central power generating stations, cogeneration can be cost-effective even in very small capacities, e.g., as low as 50 to 100 kW. Furthermore, most cogeneration projects have a much shorter lead time than the large central generating stations.
Another emerging method includes integration of solar concentration technologies with cogeneration gas turbine power/steam generation technologies, especially for large-scale applications. The conversion of cogeneration plants that are based on gas turbine cycles to integrated solar cogeneration gas turbine cycles (ISCGC) begins with adding an additional source of heat, such as solar energy, to reduce fossil fuel (e.g., natural gas) consumption, and thereby improves overall plant efficiency and reduces greenhouse gas emission, as well as other environmental pollution associated with the combustion of fossil fuels. There are other advantages of such a system, even when compared with stand-alone concentrated solar power (CSP) plants, which need the addition of expensive, bulky energy storage systems. For example, the ISCGC uses existing components, such as steam generators, a steam turbine, and a condensing system, which results in reduced installation costs of a typical CSP system. Concentration solar cogeneration power plants (CSCPP) have been shown to provide a key solution for the pressing freshwater deficits in the Middle East and North Africa (MENA) region, and could be used in the future for exporting electricity to Europe.
While the above provides some efficient and economic alternatives to the conventional fossil fuel and/or central power plants, there is still a need to increase productivity and efficiency in such systems. Thus, an integrated solar-gas turbine cogeneration plant solving the aforementioned problems is desired.